The development of resilient flooring products (i.e. non-textile) based on polymers besides polyvinyl chloride (PVC) has been an objective for a long time. For example, acrylic polymers have been disclosed as a binder for flooring products. U.S. Pat. No. 3,575,785 discloses a flooring product comprising poly alkyl methacrylate binder. World Patent Application WO 1994/9415014A1 discloses a floor tile having a binder comprising ethylene butylacrylate copolymer. WO 94/21721 discloses flooring having a wear layer comprised of plasticized acrylic polymers.
Ethylene vinyl acetate (EVA) co-polymers have also been disclosed as a binder for flooring products. For example, U.S. Pat. No. 5,244,942 discloses flooring having an EVA binder and filler. The composition may also contain polypropylene or ethylene-propylene diene monomer (EPDM) polymers as additives. U.S. Pat. Nos. 5,928,754; 6,380,296; 5,407,617; 4,614,556; and EP 0,721,829B1 disclose the use of EVA as a binder in flooring products. U.S. Pat. No. 5,276,082 discloses the use of silane-grafted EVA as a flooring binder.
Functionalized polyolefins such as ethylene acrylic acid co-polymers and their partially neutralized counterparts (ionomers) have also been disclosed as a binder for flooring products. For example, U.S. Pat. No. 4,083,824 discloses a non-vinyl flooring composition comprising (1) a copoly block acrylate comprising at least two C.sub.1 to C.sub.8 linear or branched alkyl acrylates of Mw from about 100,000 to about 300,000 and further characterized by at least two glass transition temperatures, one being above 25.degree. C., the other being below 25.degree. C.; and (2) a random ionic copolymer comprising ethylene and 2.5% to 25% by weight acrylic acid or methacrylic acid partially neutralized by a monovalent or polyvalent metal ion, said ionic copolymer having a melt index of 0.1 to 1000 grams per minute.
U.S. Pat. No. 5,391,612 discloses a flooring product comprising ethylene acrylic acid (EAA) or ethylene methacrylic acid (EMA) copolymers as binders for flooring products.
US Patent Application No. 2005/0048277 discloses a non-vinyl flooring including a binder having a terpolymer comprising ethylene, methyl acrylate and acrylic acid and a copolymer comprising ethylene and methacrylic acid. The non-vinyl flooring may be either a resilient non-vinyl floor tile or a resilient non-vinyl sheet flooring comprising the non-vinyl terpolymer and a copolymer.
U.S. Pat. Nos. 5,728,476; 5,753,767; 5,798,413; 6,921,791; and EP 0,848,037; and WO Application 2004/069920A1 also disclose the use of acid functionalized or ionomer polymers as binders in flooring product.
Polyolefin materials have also been disclosed as binders for flooring products. Recent advances in metallocene catalysts have provided new polyolefin materials of interest. Polyolefin binders are disclosed in the following patents: U.S. Pat. Nos. 6,103,803; 6,254,956; 6,356,658; 6,224,804; 5,763,501; 6,287,706; 6,017,586; 5,945,472; 6,187,424; 6,214,924; 5,700,865; 6,617,008; 5,997,782; 5,928,754; 5,824,727; and EP 0,861,951B1.
Aromatic esters and some low molecular weight polyesters have been traditionally used as plasticizers for PVC. U.S. Pat. No. 4,595,626 discloses unsaturated, cross-linkable unsaturated polyesters resins as flooring binders. The end group analysis molecular weight of the polyester is between 600 and 3600. The composition also comprises reactive monomer diluent.
PCT Application WO 95/17568 discloses a wear surface for flooring comprising a thermoset polyester resin and an epoxy or carboxyl-functional acrylic resin and a cross-linking agent. Additionally, U.S. Pat. No. 6,911,263 discloses a wear surface for flooring comprising a composite of PET (polyethylene terephthalate) clear film and a sol gel type surface coating.
Most recently, interest in polylactic acid based polyesters (PLA) has increased since the polymer can be obtained from natural resources and bio-processes. This has given rise to a large number of patents based upon these materials and other alpha-hydroxy acid based polyesters. Due to the polymer structure, these PLA polyesters require the use of plasticizers or other polymer additives for processing and to produce products having acceptable properties. For example, see U.S. Pat. Nos. 6,869,985 and 7,029,750, and US Patent Application No. 2005/0136259 which disclose compositions comprising PLA as a binder component for flooring.
Although there is a still controversy over the manufacture, use, and disposal of polyvinyl chloride, only recently have commercial efforts been made to develop materials and polymers from renewable resources. For example, DuPont's new Sorona fiber comprises a polyester made from terephthalic acid and Bio-produced 1,3-propanediol.
Recently, the US Green Building Council has established the LEED (Leadership in Energy and Environmental Design) system for scoring points for new commercial construction (Table 1). Under the LEED system, flooring can be used to obtain points if it contains 10% by weight or more of post-industrial recycle material.
TABLE 1LEED System for New Commercial ConstructionRatingLEED-NCRatingLEED-EBSystemVersion 2.1SystemVersion 2.0MR Credit5% wt =MR Credit10%4.1(post-consumer + ½ post-2.1(Post-consumer1 pointindustrial)1 pointmaterials), orMR Credit10% wt =20%4.2(post-consumer + ½ post-(Post-industrial1 pointindustrial)materials)MR Credit5% wt =MR Credit50%6(rapidly renewable building2.5(Rapidly renewable1 Pointmaterials and products)1 pointmaterials)NC: New Construction; EB: Existing Building; Minimum % wt for each point. The % for both NC and EB is weight percent.For NC 1 point is granted for at least 5% wt of the total of post-consumer and ½ post-industrial. A second point is granted for at least 10% wt of the total of post-consumer and ½ post-industrial. An additional point is granted for at least 5% wt of rapidly renewable building materials and products.For EB 1 point is granted for at least 10% wt post-consumer materials. A second point is granted for at least 20% wt of post-industrial materials. An additional point is granted for at least 50% wt of rapidly renewable materials.
There has been renewed market interest in giving preference to “greener” flooring products based upon this LEED System. The use of renewable materials is of high interest.
There continues to be a need for flooring products having a polymeric binder that comprises components obtained from renewable resources. Additionally, there is a need for such a new binder system to be compatible with existing processes and equipment currently utilized for vinyl flooring manufacturing.